LLVM  8.0.0svn
PackedVector.h
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1 //===- llvm/ADT/PackedVector.h - Packed values vector -----------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the PackedVector class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ADT_PACKEDVECTOR_H
15 #define LLVM_ADT_PACKEDVECTOR_H
16 
17 #include "llvm/ADT/BitVector.h"
18 #include <cassert>
19 #include <limits>
20 
21 namespace llvm {
22 
23 template <typename T, unsigned BitNum, typename BitVectorTy, bool isSigned>
25 
26 // This won't be necessary if we can specialize members without specializing
27 // the parent template.
28 template <typename T, unsigned BitNum, typename BitVectorTy>
29 class PackedVectorBase<T, BitNum, BitVectorTy, false> {
30 protected:
31  static T getValue(const BitVectorTy &Bits, unsigned Idx) {
32  T val = T();
33  for (unsigned i = 0; i != BitNum; ++i)
34  val = T(val | ((Bits[(Idx << (BitNum-1)) + i] ? 1UL : 0UL) << i));
35  return val;
36  }
37 
38  static void setValue(BitVectorTy &Bits, unsigned Idx, T val) {
39  assert((val >> BitNum) == 0 && "value is too big");
40  for (unsigned i = 0; i != BitNum; ++i)
41  Bits[(Idx << (BitNum-1)) + i] = val & (T(1) << i);
42  }
43 };
44 
45 template <typename T, unsigned BitNum, typename BitVectorTy>
46 class PackedVectorBase<T, BitNum, BitVectorTy, true> {
47 protected:
48  static T getValue(const BitVectorTy &Bits, unsigned Idx) {
49  T val = T();
50  for (unsigned i = 0; i != BitNum-1; ++i)
51  val = T(val | ((Bits[(Idx << (BitNum-1)) + i] ? 1UL : 0UL) << i));
52  if (Bits[(Idx << (BitNum-1)) + BitNum-1])
53  val = ~val;
54  return val;
55  }
56 
57  static void setValue(BitVectorTy &Bits, unsigned Idx, T val) {
58  if (val < 0) {
59  val = ~val;
60  Bits.set((Idx << (BitNum-1)) + BitNum-1);
61  }
62  assert((val >> (BitNum-1)) == 0 && "value is too big");
63  for (unsigned i = 0; i != BitNum-1; ++i)
64  Bits[(Idx << (BitNum-1)) + i] = val & (T(1) << i);
65  }
66 };
67 
68 /// Store a vector of values using a specific number of bits for each
69 /// value. Both signed and unsigned types can be used, e.g
70 /// @code
71 /// PackedVector<signed, 2> vec;
72 /// @endcode
73 /// will create a vector accepting values -2, -1, 0, 1. Any other value will hit
74 /// an assertion.
75 template <typename T, unsigned BitNum, typename BitVectorTy = BitVector>
76 class PackedVector : public PackedVectorBase<T, BitNum, BitVectorTy,
77  std::numeric_limits<T>::is_signed> {
78  BitVectorTy Bits;
79  using base = PackedVectorBase<T, BitNum, BitVectorTy,
80  std::numeric_limits<T>::is_signed>;
81 
82 public:
83  class reference {
84  PackedVector &Vec;
85  const unsigned Idx;
86 
87  public:
88  reference() = delete;
89  reference(PackedVector &vec, unsigned idx) : Vec(vec), Idx(idx) {}
90 
91  reference &operator=(T val) {
92  Vec.setValue(Vec.Bits, Idx, val);
93  return *this;
94  }
95 
96  operator T() const {
97  return Vec.getValue(Vec.Bits, Idx);
98  }
99  };
100 
101  PackedVector() = default;
102  explicit PackedVector(unsigned size) : Bits(size << (BitNum-1)) {}
103 
104  bool empty() const { return Bits.empty(); }
105 
106  unsigned size() const { return Bits.size() >> (BitNum - 1); }
107 
108  void clear() { Bits.clear(); }
109 
110  void resize(unsigned N) { Bits.resize(N << (BitNum - 1)); }
111 
112  void reserve(unsigned N) { Bits.reserve(N << (BitNum-1)); }
113 
115  Bits.reset();
116  return *this;
117  }
118 
119  void push_back(T val) {
120  resize(size()+1);
121  (*this)[size()-1] = val;
122  }
123 
124  reference operator[](unsigned Idx) {
125  return reference(*this, Idx);
126  }
127 
128  T operator[](unsigned Idx) const {
129  return base::getValue(Bits, Idx);
130  }
131 
132  bool operator==(const PackedVector &RHS) const {
133  return Bits == RHS.Bits;
134  }
135 
136  bool operator!=(const PackedVector &RHS) const {
137  return Bits != RHS.Bits;
138  }
139 
141  Bits |= RHS.Bits;
142  return *this;
143  }
144 };
145 
146 // Leave BitNum=0 undefined.
147 template <typename T> class PackedVector<T, 0>;
148 
149 } // end namespace llvm
150 
151 #endif // LLVM_ADT_PACKEDVECTOR_H
PackedVector & operator|=(const PackedVector &RHS)
Definition: PackedVector.h:140
unsigned size() const
Definition: PackedVector.h:106
void reserve(unsigned N)
Definition: PackedVector.h:112
This class represents lattice values for constants.
Definition: AllocatorList.h:24
PackedVector & reset()
Definition: PackedVector.h:114
bool operator==(const PackedVector &RHS) const
Definition: PackedVector.h:132
static T getValue(const BitVectorTy &Bits, unsigned Idx)
Definition: PackedVector.h:48
block Block Frequency true
void resize(unsigned N)
Definition: PackedVector.h:110
reference operator[](unsigned Idx)
Definition: PackedVector.h:124
#define T
static T getValue(const BitVectorTy &Bits, unsigned Idx)
Definition: PackedVector.h:31
static void setValue(BitVectorTy &Bits, unsigned Idx, T val)
Definition: PackedVector.h:38
Store a vector of values using a specific number of bits for each value.
Definition: PackedVector.h:76
PackedVector(unsigned size)
Definition: PackedVector.h:102
bool operator!=(const PackedVector &RHS) const
Definition: PackedVector.h:136
bool empty() const
Definition: PackedVector.h:104
reference(PackedVector &vec, unsigned idx)
Definition: PackedVector.h:89
static void setValue(BitVectorTy &Bits, unsigned Idx, T val)
Definition: PackedVector.h:57
void push_back(T val)
Definition: PackedVector.h:119
auto size(R &&Range, typename std::enable_if< std::is_same< typename std::iterator_traits< decltype(Range.begin())>::iterator_category, std::random_access_iterator_tag >::value, void >::type *=nullptr) -> decltype(std::distance(Range.begin(), Range.end()))
Get the size of a range.
Definition: STLExtras.h:1167
T operator[](unsigned Idx) const
Definition: PackedVector.h:128
#define N
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
reference & operator=(T val)
Definition: PackedVector.h:91